Plug-in electric vehicles may be charged in a number of different ways with a variety of different power sources and charging arrangements. One particular way in which a plug-in electric vehicle may be charged is via an external high-voltage charger, such as one that is part of a charging station or kiosk and provides 200V-600V of DC power. One advantage of charging a plug-in electric vehicle with an external high-voltage charger is the rapid rate of charging. This type of charging arrangement, which is also called “fast charging,” can significantly reduce charging times as it may provide between 10 kW-300 kW of charging power. The term “fast charging,” as used herein, includes any charging event or arrangement where an external power source charges a plug-in electric vehicle with a charge rate that exceeds the C-Rate of the vehicle's battery (i.e., the theoretical amount of current the battery can deliver when discharged in one hour to the point of 100% depth of discharge). For example, if the vehicle battery has a C-Rate of 45 Amp-hours, then any charging event exceeding 45 Amps could be considered a “fast charging” event.
Conventionally, the duration of a future fast charging process may be quoted based on a nominal battery temperature. However, as battery temperature varies during, for example, a drive cycle leading up to the performance of the charging process, the amount of time required to complete the charging process may be significantly longer or shorter than the quoted duration. This may be because, for example, some of the power provided by the charging station that would ordinarily be applied to the battery for charging purposes may be diverted to a thermal management system used to cool the battery. To avoid providing a vehicle user a prediction of a charging process duration that may be wholly inaccurate, such a prediction is often not made until after the charging process commences to allow for a more accurate battery temperature to be obtained, which may then be used instead of a nominal temperature to predict the duration of the charging process.
While possibly providing a more accurate prediction of charging process duration as compared to conventional techniques that use a nominal battery temperature, one drawback of this technique is that the prediction cannot be made until after the charging process commences. As a result, the vehicle user does not know how long the charging process will take ahead of time, and therefore, cannot factor it into his/her trip planning. As such, the amount of time a trip may take may be significantly different (increased) from what the user expects due to the unknown amount of time that may be added to the trip due to the performance of one or more charging processes.